Facial Muscles

Question 1

Why is vision important?

Answer 1

for balance, communication, and locating / receiving info from environment

Question 2

How is position of eyes controlled?

Answer 2

skeletal muscle

Question 3

What muscles roll eyeballs up? And down?

Answer 3

superior rectus (up)inferior rectus (down)

Question 4

What muscles roll eyeballs laterally? And medially?

Answer 4

lateral rectus (laterally)medial rectus (medially)

Question 5

What muscles roll eyeballs up and medial? And down and lateral?

Answer 5

inferior oblique (up and medial)superior oblique (down and lateral)

Question 6

What function does occulotomotor ROM give us, and how is it evaluated?

Answer 6

“smooth pursuits” - tracking in a coordinated way.Evaluate with “H” test and diagonal test

Question 7

How is ocular alignment evaluated?

Answer 7

Test by covering one eye. If the other eye deviates inward, that is esotropia. If it deviates outward, that is ecotropia.

Question 8

What is saccades and how is it evaluated?

Answer 8

Saccades is sequenced rapid eye movement between fixation points. It turns off peripheral vision, so is useful for an activity such as reading. Test by using two points in front of pt’s eyes and having them adjust back and forth. It is more difficult when points are closer.

Question 9

What is convergence and how is it evaluated?

Answer 9

Convergence is adduction of both eyes at the same time while still seeing just one object. Evaluate by having pt follow your finger while you bring it closer to their nose.

Question 10

How do OTs work in optometry?

Answer 10

On eye retraining and ADL retraining.

Question 11

Why are muscles of facial expression important?

Answer 11

• non-verbal communication- cosmoses (improvement/correction of a disfiguring condition)??? (I THINK?)

Question 12

What is innervated by CN VII?

Answer 12

all the facial muscles and the facial nerve

Question 13

Lesions of VII can be central or peripheral. What is the difference?

Answer 13

A central nerve lesion is damage to the part that is still in the brain. A peripheral nerve lesion is damage to the part that exits the brain or any part after that. Functionally: peripheral results in paralysis of all facial muscles on side of lesion while central results in paresis (not complete paralysis) on contralateral side of lesion.

Question 14

How are facial muscles affected with a peripheral nerve lesion?

Answer 14

Flaccid paralysis in all muscles ON SAME SIDE AS LESION. - the affected side becomes smooth- chewing and handling of fluids and saliva is impaired- some speech impairment(Bell’s Palsy is a peripheral nerve issue.)

Question 15

How are facial muscles affected with a central nerve lesion?

Answer 15

Paralysis of muscle of lower face ON OPPOSITE SIDE OF LESION. - Muscles of upper face spared because there are contralateral AND ipsilateral connections there - allowing for compensation. But there are only contralateral connections for lower face.- speech, chewing, and handling of fluids all affected

Question 16

What are the motions at the temporal-mandibular joint? (TMJ)

Answer 16

mandibular depression: opening of mouthmandibular elevation: closing of mouthprotrusion: jutting chin forwardretrusion: pulling chin backlateral deviation of mandible: sliding teeth to either side

Question 17

Mandibular depression and elevation are symmetrical motions around which axis?

Answer 17

frontal

Question 18

What forms the TMJ?

Answer 18

The condyle of the mandible, the articular eminence of the temporal bone, and the articular disc between the two. (There are two of these - one on each side of the jaw.)

Question 19

What is the most used joint in the body?

Answer 19

The TMJ!

Question 20

What is the purpose of the articular disc in the TMJ, and how does it articulate with the mandible and the temporal bone?

Answer 20

• provides lubrication and cushioning- divides joint into (larger) superior and inferior space.SUPERIOR joint (temporal bone/top surface of disc) is a GLIDING JOINT.INFERIOR joint (mandible/bottom surface of disc) is a HINGE JOINT.

Question 21

What purpose do the three parts of the TMJ articular disc serve?

Answer 21

1. Anterior part attaches to joint capsule and LATERAL PTERYGOID muscle. 2. Intermediate part is weight-bearing, but thinnest part. It’s avascular and has no nerve endings. 3. Posterior part, sandwiched between temporal bone / mandible, is vascular, innervated by CN V (trigem. nerve)

Question 22

What motions are involved in mandibular depression?

Answer 22

Rotation followed by translation.

Question 23

What accounts for the first 11-25 mm of the jaw opening?

Answer 23

Rotation: Anterior rotation of the mandibular condyle on the TMJ’s articular disc. This is a LOWER JOINT movement.

Question 24

What accounts for the rest of the jaw opening, beyond 25 mm?

Answer 24

Translation: The whole condyle/disc complex moves anteriorly and inferiorly (forward and down) along the articular eminence of the temporal bone. This is an UPPER JOINT movement.

Question 25

What is the total opening of the jaw?

Answer 25

40-50 mm

Question 26

What motions are involved in mandibular elevation?

Answer 26

Posterior translation followed by posterior rotation.

Question 27

What motions are involved in protrusion?

Answer 27

• translation only, no rotation - occurs in UPPER JOINT- all parts of mandible move the same amount- posterior attachments of disc are stretched- total movement is 6-9 mm

Question 28

What motions are involved in retraction?

Answer 28

• translation only, no rotation - only moves 3 mm- movement limited by soft tissue in post. joint space

Question 29

What is lateral deviation of jaw and how does it take place?

Answer 29

Asymmetrical movement of jaw that takes place in two ways. Both lateral deviations are combined into motion for chewing gum / grinding food. - Ctr of mandible moves 8 mm to side: 1 condyle spins in transverse plane, other moves forward. VERTICAL AXIS.- Ctr of mandible moves down, then deviates to spinning side. 1 condyle spins in frontal plane, other moves down. SAGITTAL AXIS.

Question 30

Why do cervical muscles in the TMJ?

Answer 30

They are stabilizers for efficient jaw movement.

Question 31

What are the muscles of mandibular depression?

Answer 31

• Digastric is the primary muscle. - Lateral pterygoid does translation of disk/condyle- Gravity helps

Question 32

What are the muscles of mandibular elevation?

Answer 32

• temporalis, masster and medial pterygoid- these are stronger than muscles of depression

Question 33

What are the muscles of protrusion and retrusion?

Answer 33

protrusion: bilateral action of masseter, both pterygoid musclesretrusion: posterior fibers of temporalis, digastric

Question 34

What are the muscles of lateral deviation?

Answer 34

• unilateral action of various muscles- both pterygoids deviate jaw to opposite side, but mostly lateral- temporalis deviates jaw to same side

Question 35

What is the difference between the lateral and medial pterygoids?

Answer 35

The lateral pterygoid muscle does translation in mandibular depression, so is the only muscles that can open the mouth.

Question 36

What causes TMJ dysfunction?

Answer 36

• often cause by the disc moving out of place- can be result of trauma, poor posture and bad oral habits like teeth grinding

Question 37

What is reciprocal click?

Answer 37

• An anteriorly dislocated disc. Causes audible click when mouth opens; quieter click when it closes. - happens because condyle not in contact with disc at rest; when mouth opens, it slips into place with a click

Question 38

What causes decreased mouth opening?

Answer 38

• anterior disc does not reduce, so blocks translation- can have just one side blocked, causing lateral deviation during depression or protrusion

Question 39

What is jaw subluxation?

Answer 39

• opening greater than 50 mm- can be bilateral or unilateral